Well, bash offers vi and Emacs as editing modes. We're already covered on that front. Many of the parameters for ls are cryptic, making it awkward to use for anything other than routine tasks without referencing the man page. more is so limited that many people choose to use a program used to concatenation files (cat) as a file viewer. Those who don't want to reach for their mouse to use their terminal's scrollbar buffer will use less, since it does more than more. Don't bother parsing that last sentence with bison, unless you have a yacc to shave.
That is an interesting point to bring up, because this type of "almost but not quite right" is exactly what AI seems to naturally create.
I recommend this book to anyone remotely interested in design. Even today it is fantastic.
Emacs and/or vi, depending on your inclination, have text editors covered already, of course ;-)